Instrument and method for reducing and securing spinal rods

ABSTRACT

A method for reducing a fixation rod is provided. The method minimizes the surgical corridor by performing fixation within the surgical corridor defined by the screw extender. The screw extender is attached to the spinal implant. The method includes the steps of coupling the proximal end of a first cannulated body with the screw extender and rotating a second cannulated body within the first cannulated body. The method proceeds to the step of actuating a rod pusher with a first driving feature so as to engage the rod pusher with the fixation rod. The rod pusher includes a bore. The method proceeds to the step of rotating an inserter shaft within first cannulated body, second cannulated body and bore of the rod pusher, the inserter shaft including a proximal end with a second driving feature and a distal end with a setscrew attachment feature.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. application Ser. No.13/957,218 filed Aug. 1, 2013, which claims priority from U.S.Provisional Application Ser. No. 61/679,294, filed on Aug. 3, 2012 andentitled “MIS Rod Inserter with Set Screw Inserter” which isincorporated herein by reference in its entirety.

FIELD

The present disclosure generally relates to the field of spinalorthopedics, and more particularly to instruments and methods forreducing and securing spinal rods within a spinal fixation system.

BACKGROUND

The spine is a flexible column formed of a plurality of bones calledvertebrae separated by cartilaginous disks. The spine includes sevencervical (neck) vertebrae, 12 thoracic (chest) vertebrae, five lumbar(lower back) vertebrae, and the fused vertebrae in the sacrum and coccyxthat help to form the hip region. While the shapes of individualvertebrae differ among these regions, each is essentially a short hollowtube containing the bundle of nerves known as the spinal cord.Individual nerves, such as those carrying messages to the arms or legs,enter and exit the spinal cord through gaps between vertebrae. Thedifferent vertebrae are connected to one another by means of articularprocesses and intervertebral, fibrocartilaginous bodies.

The spinal disks act as shock absorbers, cushioning the spine, andpreventing individual bones from contacting each other. Disks also helpto hold the vertebrae together. The weight of the upper body istransferred through the spine to the hips and the legs. The spine isheld upright through the work of the back muscles, which are attached tothe vertebrae. While the normal spine has no side-to-side curve, it doeshave a series of front-to-back curves, giving it a gentle “S” shape. Thespine curves in at the lumbar region, back out at the thoracic region,and back in at the cervical region.

Various spinal disorders may cause the spine to become misaligned,curved, and/or twisted or result in fractured and/or compressedvertebrae. It is often necessary to surgically correct these spinaldisorders. Spinal fusion is a procedure that promotes fusing or growingtogether of two or more vertebrae in the spine. Spinal fusion can beperformed to straighten a spine deformed by scoliosis, neuromusculardisease, cerebral palsy, or other disorders; prevent furtherdeformation; support a spine weakened by infection or tumor; reduce orprevent pain from pinched or injured nerves; or compensate for injuredvertebrae or disks. The procedure may improve posture, increase abilityto ventilate the lungs, prevent pain, or treat spinal instability andreduce the risk of nerve damage.

One of the types of spinal fusion procedures is a posterior spinalfusion surgery. This procedure is performed posteriorly, or from theback of patient, as opposed to anteriorly, or through the abdomen.Generally the correct curvature is obtained by manipulating thevertebrae into their proper position and securing that position with arigid system of screws and rods. The screws may be inserted into thepedicles of the vertebrae to act as bone anchors, and the rods may beinserted into heads of the screws. Two rods may run substantiallyparallel to the spine and secure the spine in the desired shape andcurvature. Thus the rods, which are shaped to mimic the correct spinalcurvature, force the spine into proper alignment. Bone grafts are thenplaced between the vertebrae to aid in fusion of the individualvertebrae together to form a correctly aligned spine.

There have been various approaches and systems for performing posteriorspinal surgery. Some conventional systems include titanium constructionthat is compatible with current CT and MRI scanning technology, lowprofile implant systems, top-loading and top-tightening systems, andother parameters. Some systems also include cross-connectors that allowa one-piece implant to be applied to a dual-rod construct for atop-loading approach.

In minimally invasive surgery (MIS), access to the screws may beseverely limited to the space provided by extenders or extension membersattached to the screw heads. For example, an exemplary posterior systemincluding screws and extenders may be found in commonly assigned U.S.Application Pub. No. 2010/0036443, entitled “Systems and Methods forSpinal Fixation” filed on Aug. 11, 2009 to Hutton et al. The system maybe used in a MIS setting. The extenders may attach to the screw heads ata distal end and extend outside the MIS surgical opening at a proximalend. The extenders are generally tubular and may also include slotsalong their lengths for insertion of fixation rods. The extendersinclude a cannula extending from the proximal end to the distal end forinsertion of various instruments and setscrews. For example, one or moreinstruments may be required to position the fixation rods into the headsof the screws, seat the rods within the heads, insert set screws toretain the rods within the heads, and tighten the set screws to rigidlyfix the system together to ensure proper bone fusion.

A typical rod reduction instrument may include a cannulated tube thatslides over the screw extender. For example, the reduction instrumentmay include a cannula through which the screw extender may slide. Thus,the reduction instrument may include a larger footprint than thesurgical opening. The larger footprint may increase the size of thesurgical opening. The reduction instrument may also inhibit loading andinsertion of a setscrew used to secure the rod within the screw head.For example, after reduction of the rod into the screw head, a separateinstrument may be used to insert the setscrew and advance the setscrewinto the screw head to fix the rod therein.

SUMMARY

An instrument for reducing a fixation rod within a screw extender thatattaches to a spinal implant includes first, second, and thirdcannulated bodies and an inserter shaft. The first cannulated bodyincludes a proximal end that couples with the screw extender. The secondcannulated body rotates within the first cannulated body and includes aproximal end with a first driving feature and a distal end with aninternal threaded portion. The third cannulated body includes a proximalend that engages the internal threaded portion and a distal end with arod pusher for engaging the fixation rod. The inserter shaft rotateswithin the third cannulated body and includes a proximal end with asecond driving feature and a distal end with a setscrew attachmentfeature.

In other features, rotation of the second cannulated body positions thethird cannulated body to reduce the fixation rod within at least one ofthe screw extender and the spinal implant. The setscrew attachmentfeature retains a setscrew rotates to engage the setscrew with thespinal implant for securing the fixation rod within the spinal implant.The rod pusher includes a pair of cantilevered arms extending distallyaway from the third cannulated body. The first driving feature attachesto a removable handle for rotating the second cannulated body. The firstcannulated body couples with the screw extender by a threadedconnection. The rod pusher includes a ridge for engagement with a slotwithin the screw extender. The rod pusher includes a curved engagementsurface configured to engage a curved surface of the fixation rod.

In still other features, the instrument includes a quick connect sleevefor coupling the first cannulated body with the screw extender. Theinstrument includes a handle including a first actuation feature thatengages the first driving feature and a second actuation feature thatengages the second driving feature.

A method for reducing a fixation rod within a screw extender thatattaches to a spinal implant includes the steps of coupling a proximalend of a first cannulated body with the screw extender; rotating asecond cannulated body within the first cannulated body, the secondcannulated body including a proximal end with a first driving featureand a distal end with an internal threaded portion; engaging proximalend of a third cannulated body with the internal threaded portion;engaging a rod pusher on a distal end of the third cannulated body withthe fixation rod; and rotating an inserter shaft within the thirdcannulated body, the inserter shaft including a proximal end with asecond driving feature and a distal end with a setscrew attachmentfeature.

In other features, rotating the second cannulated body positions thethird cannulated body to reduce the fixation rod within at least one ofthe screw extender and the spinal implant.

In still other features, the method includes the steps of retaining asetscrew on the setscrew attachment feature and engaging the setscrewwith the spinal implant for securing the fixation rod within the spinalimplant; engaging the fixation rod with a pair of cantilevered armsextending distally away from the third cannulated body; attaching aremovable handle to the first driving feature and rotating the secondcannulated body; coupling the first cannulated body with the screwextender by a threaded connection; engaging a ridge of the rod pusherwith a slot within the screw extender; engaging a curved engagementsurface of the rod pusher with a curved surface of the fixation rod;coupling the first cannulated body with the screw extender with a quickconnect sleeve; and engaging a first actuation feature of a handle withthe first driving feature and a second actuation feature of the handlewith the second driving feature.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are perspective views of a first exemplary instrumentfor reducing and securing spinal rods according to the principles of thepresent disclosure.

FIG. 2 is an exploded view of a screw extender system, the firstexemplar instrument, and a handle according to the principles of thepresent disclosure.

FIG. 3 a perspective view of the instrument and handle engaged with thescrew extender system to reduce and secure a spinal rod according to theprinciples of the present disclosure.

FIG. 4 is an exploded view of the first exemplary instrument accordingto the principles of the present disclosure.

FIG. 5 is an exploded view of first and second cannulated bodies of thefirst exemplary instrument according to the principles of the presentdisclosure.

FIGS. 6A and 6B are side views of the first exemplary instrument in aretracted position prior to a reduction step and during the reductionstep according to the principles of the present disclosure.

FIGS. 7A and 7B are cross-sectional views of the instrument of FIGS. 6Aand 6B along planes VII-A and VII-B according to the principles of thepresent disclosure.

FIG. 8 is a perspective view of the handle according to the principlesof the present disclosure.

FIGS. 9A and 9B are side and cross-sectional views along the plane IX-Bof the handle of FIG. 8 according to the principles of the presentdisclosure.

FIGS. 10A and 10B are side views of the first exemplary instrumentreducing the fixation rod within the screw extender system according tothe principles of the present disclosure.

FIGS. 11A and 11B are cross-sectional views of the instrument of FIGS.10A and 10B along the planes XI-A and XI-B respectively according to theprinciples of the present disclosure.

FIGS. 12A and 12B are enlarged views of the instrument of FIGS. 11A and11B in circled areas XII-A and XII-B respectively according to theprinciples of the present disclosure.

FIGS. 13A and 13B are side and cross-sectional views along the planeXIII-B of a second exemplary instrument for reducing the fixation rodwithin a screw extender system according to the principles of thepresent disclosure.

FIG. 14 is an exploded view of the instrument of FIGS. 13A and 13Baccording to the principles of the present disclosure.

DETAILED DESCRIPTION

Each of the instruments and methods for reducing and securing a spinalrod of the present disclosure includes features that provide a decreasedfootprint for insertion within the cannula of a screw extender. Each ofthe instruments includes features for preloading and insertion of asetscrew to secure the spinal rod within the head of a previouslyinserted screw. Each of the instruments includes features for easy andquick attachment to the screw extender and features various driverattachments for reducing and/or advancing the setscrew to rigidly securethe fixation rod within the head of the screw.

Embodiments of the invention will now be described with reference to theFigures, wherein like numerals reflect like elements throughout. Theterminology used in the description presented herein is not intended tobe interpreted in any limited or restrictive way, simply because it isbeing utilized in conjunction with detailed description of certainspecific embodiments of the invention. Furthermore, embodiments of theinvention may include several novel features, no single one of which issolely responsible for its desirable attributes or which is essential topracticing the invention described herein. The words proximal and distalare applied herein to denote specific ends of components of theinstrument described herein. A proximal end refers to the end of aninstrument nearer to an operator of the instrument when the instrumentis being used. A distal end refers to the end of a component furtherfrom the operator and extending towards the surgical area of a patientand/or the implant.

FIGS. 1A and 1B illustrate perspective views of a first exemplaryinstrument 100 for reducing a fixation rod within a receiving portion ofthe screw head and inserting a setscrew to rigidly secure the rod to thehead. For example, as illustrated in FIGS. 2 and 3, the instrument 100may be used with a minimally invasive surgery (MIS) system comprisingone or more screw extenders 300, screw assemblies 400, and fixation rods500. Exemplary MIS systems with similar screws, extenders, and rods maybe found in commonly assigned U.S. Pub. No. 2010/0036443. However,features of the instrument 100 may be compatible with various other MISsystems known in the art. The instrument 100 may be used with actuationmeans such as a handle 600 that connects with the instrument 100.

The instrument 100 includes various features to reduce the fixation rod500 into a receiving portion 402 of the screw assembly 400 and insert asetscrew 404 to retain the fixation rod 500 therein. As illustrated inFIG. 3, the instrument 100 may be inserted into the screw extender 300and couple at its proximal end. A distal end of the screw extender 300couples with the receiving portion 402 of the screw assembly 400. Thehandle 600 attaches to the proximal end of the instrument 100 andincludes features to actuate the instrument 100. The fixation rod 500may be inserted into the distal end of the screw extender 300 while theinstrument 100 is in the retracted position. The fixation rod 500 may beadvanced distally as the instrument 100 moves towards the extendedposition. The fixation rod 500 may be fully seated within the receivingportion 402 of the screw assembly 400 when the instrument 100 is in theextended position. Once the fixation rod 500 is fully seated, the handle600 may include a second actuating feature 604 for actuating theinstrument 100 to advance the setscrew 404 into the receiving portion402 of the screw assembly 400 to rigidly couple the fixation rod 500therein.

Continuing now also with FIGS. 4 and 5, the instrument 100 may include aplurality of concentric bodies and shafts that rotate relative to oneanother to linearly displace features that apply force on the fixationrod 500. Various features may engage the screw extender 300 and retainand drive the setscrew 404 to lock the fixation rod 500 with the screwassembly 400. The instrument 100 includes a first body 102, a secondbody 104, and a third body 106. The first body 102 includes firstcannula 108 that receives the second body 104. The first cannula 108 maybe substantially smooth from a proximal end to a distal end of the firstbody 102 which permits rotation of the second body 104 therein. At theproximal end of the first body 102, coupling means, such as an externalthread 110, may be configured to couple with mating threads 302 on aproximal end of a screw extender 300 as shown in FIG. 2.

The second body 104 extends through the first cannula 108 and mayinclude retaining portions, such as a proximal cap 112 and a distal lip114 that extend outside the first cannula 108 and retain the second body104 therein. The proximal cap 112 and distal lip 114 may retain thesecond body 104 within the first body 102 while permitting rotationwithin the first cannula 108. The proximal cap 112 may removably couplewith the second body 104 to retain the second body 104 within the firstcannula 108. The proximal cap 112 may include a first driving feature116 that mates with features of the handle 600 for rotating the secondbody 104 within the first body 102. For example, first driving feature116 may include a recessed portion including a first geometry such as arectangular or square shape that mates with corresponding geometry of afirst actuating shaft 602 of the handle 600. As the first drivingfeature 116 is rotated, one or more portions of the second body 104 mayrotate in the same direction.

The second body 104 includes a second cannula 118 that receives thethird body 106. At a distal end of the second cannula 118, an internallythreaded portion 120 may be configured to engage features of the thirdbody 106 as illustrated in detail with FIGS. 7A and 7B. The third body106 includes a proximal end that engages the internally threaded portion120 of the second cannula 118. For example, the proximal end may includea mating external threaded portion 122 for threaded engagement with thesecond cannula 118. The third body 106 includes a distal end thatengages the fixation rod 500 as described herein. For example, thedistal end may include a rod pusher 124 for engaging the fixation rod500. The rod pusher 124 includes a substantially cylindrical profile.The rod pusher 124 may include one or more arms 126 extending distallyaway from the third body 106. For example, the arms 126 may cantileveraway from the sides of the rod pusher 124. The arms 126 may terminate incontoured tips 127 conforming to the radius of the fixation rod 500.

The third body 106 may include a third cannula 128 for receiving aninserter shaft 130. The inserter shaft 130 may include features forretaining, inserting, and driving the setscrew 404. In the presentexample, the inserter shaft 130 includes an elongated, cylindricalprofile extending from a proximal end to a distal end. The insertershaft 130 may rotate freely within the third cannula 128. The proximalend of the inserter shaft 130 may extend proximally through the secondcannula 118 and past the first driving feature 116. The proximal end ofthe inserter shaft 130 may include a second driving feature 132 thatmates with an actuator for rotating the inserter shaft 130 within thethird body 106. For example, the second driving feature 132 may includea shaped portion of the inserter shaft 130 including a second geometrysuch as a rectangular or square shape. As the second driving feature 132is rotated, the inserter shaft 130 may rotate in the same direction. Thedistal end of the inserter shaft 130 may extend outside the thirdcannula 128 and include an attachment feature 134 such as a hexalobe orsplined pattern. The attachment feature 134 may retain the setscrew 404by frictional engagement with a recessed portion of the setscrew 404 asknown in the art.

Other features of the instrument 100 may include a coupler for quickconnect and secure coupling of the instrument 100 to the screw extender300. The coupler may include an outer sleeve 136, an inner sleeve 138,and a bias mechanism 140. Pins 142 extending radially from the proximalend of the first body 102 may pass through slots 144 in the outer sleeve136 and slots 146 in the inner sleeve 138 and permit the coupler toslide relative to the first body 102. The bias mechanism 140 may biasthe sleeves 136 and 138 distally or proximally. To attach the instrument100 to the screw extender 300, the user may compress or expand the biasmechanism 140 to engage the external thread 110 on the first body 102with the mating threads 302 of the screw extender 300. In otherfeatures, a limit pin 148 may extend through a transverse slot 150 inthe inserter shaft 130. The limit pin 148 may limit advancement of theinserter shaft 130 distally through the third cannula 128 by engagementwith the proximal end of the third body 106. For example, ends of thelimit pin 148 may extend outside the transverse slot 150 to engage thedistal end of the third body 106 as the inserter shaft 130 slidesdistally through the third cannula 128. Thus, the inserter shaft 130 mayrotate freely in the third cannula 128 but not pass completely throughthe third cannula 128.

FIGS. 6A-7B illustrate additional views of the instrument 100 in bothretracted (FIGS. 6A and 7A) and extended (FIGS. 6B and 7B) positions asused with MIS systems. In the retracted position, the instrument 100includes a first overall length L1 as measured from a top surface of theproximal cap 112 to the contoured tips 127 of the arms 126. As thesecond body 104 rotates, the external threaded portion 122 of the rodpusher 124 engages the internally threaded portion 120 of the secondcannula 118. Rotation in a first direction, such as a clockwisedirection, causes the rod pusher 124 to extend distally. Rotation in asecond direction, such as a counter-clockwise direction, causes the rodpusher 124 to retract proximally. In the extended position, theinstrument includes a second overall length L2 as measured from the topsurface of the proximal cap 112 to the contoured tips 127 of the arms126. The second length L2 may be greater than the first length L1. Boththe first length L1 and the second length L2 may be less than a lengthL3 of the screw extender 300 as shown in FIG. 2. The inserter shaft 130may freely float within the third cannula 128 as the rod pusher 124retracts and extends relative to the second body 104. The limit pin 148limits movement of the inserter shaft 130 distally by engaging the uppersurface of the rod pusher 124.

FIGS. 8-9B illustrate additional features of the handle 600 foractuation of the instrument 100. The handle 600 includes a handle body606 with the second actuating feature 604 at its distal end. The secondactuating feature 604 may engage the first driving feature 116 of theinstrument 100. For example, the second actuating feature 604 mayinclude a shaped portion of the handle body 606 corresponding to theshape of the first driving feature 116, such as a square or rectangularprofile. The handle body 606 may include an outer gripping surface suchas applied silicone. As the handle body 606 rotates, the secondactuation feature 604 rotates. The handle body 606 may include a fourthcannula 608 through which a handle shaft 610 extends. The fourth cannula608 may extend from a proximal end to a distal end of the handle 600.

A proximal cap 612 and a distal cap 614 may thread onto the ends of thefourth cannula 608 and include apertures through which the handle shaft610 may pass. The apertures 616 may provide bearing surfaces forimproved rotation of the handle shaft 610 within the handle body 606. Athird actuating feature 618 on the distal end of the handle shaft 610may extend outside the fourth cannula 608. The third actuating feature618 may engage the second driving feature 132 of the instrument 100. Forexample, the third actuating feature 618 may include a recessed portion620 or pocket corresponding to the shape of the second driving feature132, such as a square or rectangular profile. On the proximal end of thehandle shaft 610, a knob 622 may be used to rotate the handle shaft 610.

Referring now to FIGS. 10A-12B, the instrument 100 is shown coupledwithin the screw extender 300 that is attached to the screw assembly400. The instrument 100 may be actuated by the handle 600 to reduce thefixation rod 500 within the screw assembly 400 and insert the setscrew404 to retain the fixation rod 500 within the receiving portion 402. Forexample, the proximal end of the instrument 100 may be coupled to theproximal end of the screw extender 300 via threaded engagement and/orthe coupler sleeves 136 and 138. The first body 102, second body 104,and third body 106 extend distally into the screw extender 300.

In the retracted position as best illustrated in FIGS. 10A, 11A, and12A, the contoured tips 127 of the arms 126 may begin to engage thefixation rod 500 at some distance from the receiving portion 402 of thescrew assembly 400. The setscrew 404 may be secured to the attachmentfeature 134 of the inserter shaft 130 which floats freely within thethird cannula 128. As the handle body 606 rotates in the firstdirection, the second actuating feature 604 rotates second body 104within the first body 102 via the first driving feature 116. Therotational movement causes the rod pusher 124 to advance distally andapply force to the fixation rod 500 via the arms 126. The inserter shaft130 may follow the rod pusher 124 distally with the attached setscrew4040 floating just above the fixation rod 500. The rod pusher 124continues to advance distally until the fixation rod 500 is seatedwithin the receiving portion 402 of the screw assembly 400.

In the extended position as best illustrated in FIGS. 10B, 11B, and 12B,the contoured tips 127 of the arms 126 may continue to engage thefixation rod 500 and hold it within the receiving portion 402 of thescrew assembly 400. The setscrew 404 may be advanced by the insertershaft 130 onto threads of the receiving portion 402 by rotating the knob622 of the handle 600. As the knob 622 rotates in a first direction, forexample a clockwise direction, the setscrew 404 may engage more of thethread of the receiving portion 402 and advance distally towards thefixation rod 500. The knob 622 may rotate in a second oppositedirection, for example, a counter-clockwise direction, to remove thesetscrew 404. Once the setscrew 404 has been inserted and tightenedsufficiently, the instrument 100 may be uncoupled from the screwextender 300.

FIGS. 13A-14 illustrate another exemplary instrument 700 for reducing afixation rod within a screw extender. The instrument 700 includes afirst body 702, a second body 704, and a third body 706. The first body702 includes a first cannula 708 that receives the second body 704. Thefirst cannula 708 may be substantially smooth from a proximal end to adistal end of the first body 702 to permit rotation of the second body704 therein. The first body 702 may slide over the proximal end of ascrew extender such as screw extender 300. The second body 704 mayinclude a threaded portion 710 for engagement with the mating threads302 of the screw extender 300. A proximal end of the second body 704 mayinclude a proximal cap 712 with a driving feature 716. The drivingfeature 716 mates with features of the handle 600 for rotating thesecond body 704 within the first body 702. For example, driving feature716 may include a recessed portion including a first geometry such as arectangular or square shape that mates with corresponding geometry ofthe first actuating shaft 602 of the handle 600. As the driving feature716 is rotated, one or more portions of the second body 704 may rotatein the same direction.

The second body 704 includes a second cannula 718 that receives thethird body 706. The third body 706 includes a proximal end that engagesthe second cannula 718. For example, the proximal end may include aflexible collet 720 for engagement with one or more grooves 722 withinthe second cannula 718. The flexible collet 720 may snap into the groove722 by elastically deforming radially inward. Once the flexible collet720 couples within the groove 722, the third body 706 may rotate withinthe second cannula 718. The third body 706 includes a distal end thatengages the fixation rod 500 as described herein. For example, thedistal end may include a rod pusher 724 for engaging the fixation rod500. The rod pusher 724 includes a substantially cylindrical profile.The rod pusher 724 may include one or more arms 726 extending distallyaway from the third body 706. For example, the arms 726 may cantileveraway from the sides of the rod pusher 724. The arms 726 may terminate incontoured tips 727 conforming to the radius of the fixation rod 500.

The present exemplary instrument 700 may reduce the fixation rod 500within the screw assembly 400 by threaded engagement with mating threads302 on the screw extender 300. For example, the instrument 700 may bethreaded onto the screw extender by engaging threaded portion 710 withthe mating threads 302. The arms 726 may engage the slots 304 of thescrew extender 300. The handle 600 or other actuation instrument may beinserted into the driving feature 716 to rotate the second body 704 toeither advance the instrument 700 distally or proximally within thescrew extender 300. For example, rotating the second body 704 in a firstdirection, such as a clockwise direction, advances the instrument 700distally to engage the arms 726 with the fixation rod 500 for reduction.Rotating the second body 704 in a second direction, such as acounter-clockwise direction, retracts the instrument 700 proximally todisengage the arms 726. The third body 706 may include a third cannula728 to receive an inserter shaft similar to the inserter shaft 130 ofthe instrument 100 of FIGS. 1-12.

Example embodiments of the methods and systems of the present inventionhave been described herein. As noted elsewhere, these exampleembodiments have been described for illustrative purposes only, and arenot limiting. Other embodiments are possible and are covered by theinvention. Such embodiments will be apparent to persons skilled in therelevant art(s) based on the teachings contained herein. Thus, thebreadth and scope of the present invention should not be limited by anyof the above-described exemplary embodiments, but should be defined onlyin accordance with the following claims and their equivalents.

1. A method for reducing a fixation rod within a screw extender thatattaches to a spinal implant, comprising: coupling a proximal end of afirst cannulated body with the screw extender; rotating a secondcannulated body within the first cannulated body, the second cannulatedbody including a first driving feature; actuating a rod pusher with thefirst driving feature so as to engage the rod pusher with the fixationrod, the rod pusher having a bore; and rotating an inserter shaft withinthe first cannulated body, second cannulated body and bore of the rodpusher, the inserter shaft including a proximal end with a seconddriving feature and a distal end with a setscrew attachment feature forengaging a setscrew.
 2. The method of claim 1, wherein rotating thesecond cannulated body positions the rod pusher to reduce the fixationrod within at least one of the screw extender and the spinal implant. 3.The method of claim 1, further comprising retaining a setscrew on thesetscrew attachment feature of the inserter shaft and engaging thesetscrew with the spinal implant for securing the fixation rod withinthe spinal implant.
 4. The method of claim 1, wherein the rod pusherincludes a pair of cantilever arms.
 5. The method of claim 1, furthercomprising attaching a removable handle to the first driving feature androtating the second cannulated body.
 6. The method of claim 1, furthercomprising coupling the first cannulated body with the screw extender bya threaded connection.
 7. The method of claim 1, further comprisingengaging a ridge of the rod pusher with a slot within the screwextender.
 8. The method of claim 1, further comprising engaging a curvedengagement surface of the rod pusher with a curved surface of thefixation rod.
 9. The method of claim 1, further comprising coupling thefirst cannulated body with the screw extender with a quick connectsleeve.
 10. The method of claim 1, further comprising engaging a firstactuation feature of a handle with the first driving feature of thesecond cannulated body and a second actuation feature of the handle withthe second driving feature of the inserter shaft.
 11. The method ofclaim 1, further comprising the step of providing a third cannulatedbody, the third cannulated body disposed on the proximal end of the rodpusher, wherein the distal end of the second cannulated body includes aninternal threaded portion and engaging the proximal end of the thirdcannulated body with the internal threaded portion so as to actuate therod pusher.